For years Lee said not to fix bulged brass then they came out with the Bulge Buster and still issue a warning. There is also the old warning on the FAQ of their website;

Unsuported Chamber Warning

Glock Cases

We do not recommend "fixing" cases fired in pistols with unsupported chambers, because there is no way to make them safe once they have bulged. The case wall is thinned where it bulges, and resizing the outside of the case back down to the correct diameter does not restore the case back to its original thickness. If this case is fired in a pistol with an unsupported chamber again, and this thinned section of brass happens to line up with the unsupported part of the chamber, there is a high probability that the case will rupture.